The present invention relates to a method for measuring the length of a line using a distance measuring device, and a device for carrying out the method.
Distance measuring devices, and hand-held distance measuring devices in particular, e.g., optoelectrical distance measuring devices or ultrasonic rangefinders, have been known per se for a long period of time, and they are commercially available. These devices emit a modulated measurement beam, e.g., a light beam in the form of a laser beam, that is directed toward a desired target object whose distance from the device is to be determined. The returning measurement signal—or at least a portion thereof—that has been reflected by the target object is detected by a sensor in the device and is used to determine the distance in question between the measuring device and the target object.
Typical fields of application of devices of this type include, e.g., the trade sector, the construction industry or interior finishing, when a user wants to determine certain lines, surface areas or volumes as quickly as possible and with a high degree of accuracy. To perform a measurement, for example, a distance measuring device of this type with a reference plane assigned thereto is held against a first wall, for instance, then the operating unit is actuated and a measurement signal is emitted, in order to measure a distance to a second wall. Since, with distance measuring devices of this type, the measurement signal is typically emitted in one direction, the reference plane of the measuring device, i.e., the plane used as the reference for the distances measured with the device, must be located as precisely as possible on the zero point of the line to be determined.
Publication DE 102 53 669 A1 makes known a hand-held laser rangefinder that employs an extreme-value measurement method, with which, in a first step, input means of the hand-held laser rangefinder are actuated, thereby triggering a measurement sequence, during which, in a second step, individual distance measurements initiated by the hand-held laser rangefinder are carried out. In a third step, the hand-held laser rangefinder according to DE 102 53 669 A1 determines at least one maximum value and/or one minimum value from the sequence of individual measurements. Based on the at least one minimum value and the at least one maximum value, the hand-held laser rangefinder determines the difference between the extreme values in the sequence of measurements. Based on this extreme-value difference, it is possible to derive, e.g., the exact position of objects such as pipework or cladding relative to surfaces such as walls or ceilings. For example, the break recess of a wall can be determined using the extreme-value measurement method described in DE 102 53 669 A1.
Publication DE 198 36 812 A1 makes known a hand-held laser rangefinder for distance measurement that uses the phase or transit time measurement method, with which a large number of measurement routines for solving application-specific measuring tasks is stored in the arithemetic unit of the measurement device. These measurement routines can be called up using a button on the keypad of the measuring device and displayed in the display field of the device. After the user of the hand-held laser rangefinder described in DE 198 36 812 A1 selects a measurement routine of this type, he is prompted via a menu in the display field of the device to perform individual measurements of a path in succession. The results are used by an arithmetic unit in the measuring device to calculate a distance, surface area, or volume in question.
Based on the devices in the related art, the object of the present invention is to provide a user with a simple and, therefore, user-friendly procedure for measuring lines, thereby enabling him to determine—in particular—distances that cannot be measured directly.